Rigby's death mentioned in ''House Rules''

Hey guys! I was wondering about one thing. In ''House Rules'' episode, Mordecai from future appears and he says about Rigby ''You know what else you gonna miss? That guy. Enjoy him while you got him, know what i'm saying?''. So i was wondering what is it all about. I mean, is it some kind of weird joke about that Rigby dies or almost dies, and its hinted that he gonna die for good in the future? is it what would happened if Mordecai and Rigby would stay in ''No Rules World''? Or will we find out in new episodes or something? I also read somewhere that in ''Under the Hood'' episode it's hinted that Mordecai remember what his future self told him about Rigby but i watched this episode and i didn't found any clues. I really want to see your opinions about it and maybe cry with someone about that Rigby may die. (Rigby is my favorite character and i really don't want him dead)

Well actually...He has died a few times allready,He Almost died in "Eggcelent", Mordecai actually Killed rigby in "Its Time" but he went back in time and prevented that from happening again and When Skips Kills rigby in "Over The Top" but he revives him by winning an arm wrestling match against Death.